Zips… the ups and downs!




All boat covers need to open so you can get in and out of your boat.

In a lot of cases, this means you need a zip. A zip is easy to use and strong enough to withstand a lot of use.

But did you ever think about just what a zip is? Besides something that goes up. And down. And up. And down. over and over…..

There are a few different types of zip.

1. Continuous zip. This is used in cushions and smiley or u-zips where the end is sewn into the fabric. It’s purpose is to join 2 pieces of fabric together, and the zip is either open or closed.
2. Open-ended zip. These zips allow the 2 pieces of fabric to be completely separated, like on a jacket, or on a boat cover where panels can be removed and stored away. One half of the zip has a box at the end, the other half has a pin. These join together to do the zip up.

To complicate things more, there are a couple of ways zips are manufactured.

1. Moulded zip. These zips have individual plastic teeth. They are used for relatively straight areas.
Black Moulded Zip

Circe rear

2. Spiral zip. Also called coil zip. These are made with a plastic coil thats acts as teeth. This type is used on most garments, bags, and smiley windows on the boat covers (they are able to curve).
coil zip








u window

The zip itself consists of a few basic pieces, namely teeth, tape and slides. In the marine environment, plastic proves a better choice than metal, as it doesn’t corrode. Slides can be single, or double (can be opened from both sides). Black zips have better UV stabilisation than white zips.

Parts of the Zip












Then we come to size! We want to use something sturdy enough to handle the amount of use the cover gets, the strain and stress on the zip and the weight of the cover. The bigger the number, the more robust the teeth. A cushion will probably have a #5 continuous coil zip, with a metal slide. A side curtain will have an #10 open-ended zip, with a plastic slide. A sail cover will probably have a #15 open-ended zip with a plastic slide. #15 zips are really chunky! There are #20 (massive), but a bit of overkill in all but extreme situations.

Confused yet?
magnetic zip

We had previously also used  magnetic zips in certain applications. These are are now no longer available – effectively long piece of plastic with small round magets embedded in the strips. This allows them to be pulled apart end to end, while providing strength side to side. They were great, and we would love to be able to get them again!

Caring for your zips……
Keep them clean! If they get dirty, or sandy, or salty, give them a rinse in clean fresh water. Let them dry.


Keep a can of silicone spray handy, and spray your zips often. This will lubricate them, while not making them sticky, so sand and gunk won’t stick to them.

Silicone spray

And finally, keep your zips done up during boat storage. This will extend the life of your zip and cover.

Zip the Dog

Canvas Barn Marine Trimming has its own special “Zip”…. our little Jack Russell who joined us in 2012. She’s a boating expert!

About the author, Canvas Barn Marine Trimming

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